Pantograph assembly



y 1951 E. F. MOCALEB 2,562,727

PANTOGRAPH ASSEMBLY Filed July 18, 1950 Inventor": Eugene F? Mo Caleb,

H i S Attorney.

Patented July 31, 1 951 arm" OFFICE PANTOGRAPH ASSEMBLY Eugene F.McCaleb, Erie, Pa, assignor to General Electric Company, a corporationof New York Application July 18, 1950, Serial No. 174,415

2 (llaims.

My invention relates to pantograph assemblies, and more particularly topantograph assemblies of the type used to establish contact between anoverhead power wire and electric railway cars and the like.

When overhead wires are erected to supply power to electric railway carsand the like, the wires are subject to sagging between supports. Thesagging creates a problem in maintaining constant firm contact betweenthe car and the overhead wire as the tension in the wire varies betweenadjacent supports. Railway cars are subject to swaying when movingaround turns and when traveling over an uneven portion of the roadbedoThis increases the difficulty of maintaining satisfactory contact withan overhead wire, particularly when the car is moving at a high speed.

Therefore, an important object of my invention is to provide an improvedmeans for establishing' contact between an overhead power wire andelectric railway cars and the like which travel at high speeds.

Another object of my invention is to provide means for maintainingsubstantially constant contact pressure on an overhead power wire inspite of sagging in the line and major changes in the height of the lineabove the roadbed.

A further object of my invention is to provide means for maintainingsubstantially constant contact pressure on an overhead power wire inspite of swaying of the car.

In the attainment of the'foregoing objects an important feature of thisinvention resides in the use of a pantograph assembly pivotally mountedupon the roof of a railway car or the like, a spring-operated,extensible cylinder in combina-. tion with a plurality of rigidlinksmechanically connected to thepantograph assembly, and a bracket inparallel relationship with a pair of rigid links and a pair of arms formaintaining the contact area between a current. collecting device andan, overhead wire substantially constant. The pivotal mounting enablesthe pantograph assembly to rotate transversely toward either side of thecar in response to the swaying of thecar. The extensible cylindermaintains substantially constant contact pressure between the pantographassembly and the overhead power wire by acting through the firstmentioned rigid links to balance the force applied within the extensiblecylinder by the spring against the tension of the overhead wire and.theweight of the pantograph assembly. The bracket connected in parallelrelationship with the arms and the links maintains the currentcollecting device in a horizontal plane with respect to the car when thepantograph assembly is raised or lowered to maintain contact with theoverhead wire.

For additional objects and advantages and for a better understanding ofmy invention; attention is now directed to the following description andthe accompanying drawing and also to the appended claims in which thefeatures of the invention believed to be novel are particularly pointedout. Fig. 1 is a side elevation of a pantograph assembly embodying myinvention, and Fig. 2 is a section taken along line 22 in Fig. 1.

Referring to the'drawing, a standard l is disposed upon the top of anelectric railway car. A base block 2 is pivotally mounted upon a longitudinal shaft 3 which is supported by standard I. Shatf 3 is supportedat such a height above the base plate of standard I that base block 2may rotate transversely through a limited range in response to swayingof the car and in response to transverse displacement of the overheadpower wire with respect to the car. The lower arms 4 and 5 of thepantograph assembly are connected to base block 2 by the hinges 6 and 1respectively.

Hinges 6 and l are pivoted on transverse axes.

A cylinder 8 is disposed vertically upon the top of base block 2. Acylinder 9 having an inside diameter slightly larger than the outsidediameter of cylinder 8 is arranged concentrically around cylinder 8. Ahelical spring ID is arranged in compression within cylinder 8, bearingon base block 2 and a retaining plate I]. A bolt l2 in threadedengagement with retaining plate II and a cap [3 on cylinder 9 isprovided for adjusting the compression of spring 10. A nut I4 isprovided for locking bolt i2 in position. Rigid links and it areconnected to the top of cylinder 9 by pinning means and connected toarms 4 and 5 respectively near the lower ends thereof by hinges l1 andI8 respectively, hinges ii and I8 pivoting on transverse axes. Arms 4and 5 are connected to the upper arms [9 and of the pantograph assemblyby hinges 2| and 22 respectively, hinges 2| and 22 pivoting abouttransverse axes. An inverted, U-shaped bracket 23 is connected to armsl9 and 20 at the upper end thereof by hinges Z4 and 25, respectively,hinges Hand 25 pivoting on transverse axes.

Mounted upon the top of bracket 23 is a cur rent-collecting slider shoe26 having a 1ongitudinal aperture 21 in the surface thereof for makingcontact with the overhead wire. The'sides of aperture 21 also preventtransverse motion of shoe 26 with respect to the wire. A shunt 28 isprovided to connect shoe 26 to bracket 23 electrically. A U-shapedbracket 29 is provided on the bottom of bracket 23 for attaching meansfor manually lowering the pantograph assembly such as a cable, a pole,or the like. A pair of rigid arms 30 and 3| are connected to arms I!)and 20 near the upper ends thereof and project downward therefrom in aconverging manner. A pair of rigid links 32 and 33 are pivotallyconnected to the lower ends of arms 30 and 3| respectively and projectupward therefrom in a converging manner. A vertically slotted arm 34 issecured to and extends vertically downward from bracket 23. The upperends of links 32 and 33 are connected to arm 34 by a transverse pinthrough the ends of links 32 and 33 and the slot in arm 34.

The compressive stress on spring I is adjusted by positioning bolt l2.The force due to this compressive stress in spring I0 is transmitted tothe pantograph assembly through the cylinder 9 and links l and Hi. Whenthe cylinder 9 is raised, links l5 and I6 are drawn in toward cylinder 9thereby pivoting arms 4 and 5 upward on hinges 6 and I and raising thepantograph assembly. The upward motion is transmitted to shoe 26 throughhinges 2| and 22, arms I9 and 2D, hinges 24 and 25, and bracket 23. Thedistance through which bracket 23 is moved is much greater than thedistance through which cylinder 9 is moved because hinge 2| movesthrough a much larger arc than hinge IT. The bracket 23 maintains auniform separation between the upper ends of arms l9 and 20. If arm I9tends to drop while arm 20 is rising, bracket 23 tilts, and arm 34 tendsto move away from the lower end of arm 30. The link 32 restrains thistendency and tends to pull arm 34 back into the vertical position,thereby maintaining bracket 23 in a horizontal position with respect tothe top of the car. If arm 20 tends to drop'while arm I9 is rising, arm3| and link 33 maintain bracket 23 in a horizontal position with respectto the top of the car in the manner hereinbefore described. The upwardmotion of the pantograph assembly continues until the forces due to theweight of the pantograph assembly and the tension of the overhead wireas applied to cylinder 9 are equal to the compressive stress on springHi. When the car sways to one side or the other, or when the overheadline is displaced transversely with respect to the car, the pantographassembly pivots about shaft 3 and is extended by the action of spring Into maintain constant contact with the overhead wire.

While the present invention has been described by reference toparticular embodiments thereof, it will be understood that this is byway of illustration of the principles involved and that those skilled inthe .art may make many modifications in the arrangement and mode ofoperation. Therefore, I contemplate by the appended claims to cover anysuch modifications as fall within the true spirit and scope of thisinvention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. For use on electric railway cars and the like a pantograph assemblyfor obtaining power from an overhead wire, said pantograph assemblycomprising a pair of upper arms hingedly connected to a pair of lowerarms to form a parallelogram, a shaft longitudinally disposed on the topof said car, a base block pivotally mounted on said shaft, a pair ofhinges for con.-

necting said lower arms of said pantograph assembly to said base block,a first cylinder mounted vertically on said base block, a secondcylinder having a rigid cap on one end thereof and having an insidediameter slightly larger than the outside diameter of said firstcylinder and disposed around the upper end of said first cylinder, aretaining plate arranged within said second cylinder in a planeperpendicular to the axis of said cylinder, a spring disposed incompression within said second cylinder and bearing on said retainingplate and said base block,

a bolt extending vertically through said cap and in threaded engagementtherewith and in threaded engagement with said retaining plate foradjusting the compressive stress on said spring, a plurality of rigidlinks connecting said cap to said lower arms of said pantograph assemblyto transfer the vertical displacement of said second cylinder todisplacement of said pantograph assembly, an inverted U-shaped bracket,a pair of hinges for connecting said inverted U-shaped bracket to saidupper arms of said pantograph assembly, a current collecting devicemounted on the top of said inverted U-shaped bracket and comprising aslider shoe having a longitudinal aperture in the surface thereof forcontacting with said wire and for substantially prohibiting transversemotion of said slider shoe with respect to said wire and having a shuntfor electrically connecting said current collecting device to saidpantograph assembly, a vertically slotted arm secured to and extendingvertically downward from said inverted U-shaped bracket and disposedmidway between said last-mentioned hinges, said slotted arm connected toeach of said upper arms of said pantograph assembly by a rigid linkserially connected with a supporting arm, one end of said supporting armbeing rigidly mounted on said upper arm of said pantograph assembly,thereby causing either of said upper arms to be restrained whenever saidupper arm tends to move to an unsymmetrical position with respect to theother said upper arm.

2. For use on electric railway cars and the like a pantograph assemblyfor obtaining power from an overhead wire, said pantograph assemblycomprising a pair of upper arms hingedly connected to a pair of lowerarms to form a parallelogram, a shaft longitudinally disposed on the topof said car, a base block pivotally mounted on said shaft, a pair ofhinges for connecting said lower arms of said pantograph assembly tosaid base block, an extensible cylinder mounted vertically on the top ofsaid base block, a spring disposed in compression within said cylinderfor extending and contracting said cylinder in response to changes inthe compressive stress on said spring, a plurality of rigid linksconnecting said extensible cylinder to said lower arms of saidpantograph assembly to transfer the vertical displacement of saidextensible cylinder to displacement of said pantograph assembly, aninverted U-shaped bracket, a pair of hinges for connecting said invertedU-shaped bracket to said upper arms of said pantograph assembly, acurrent collecting device mounted on the top of said inverted U-shapedbracket and comprising a slider shoe having a longitudinal aperture inthe surface thereof for contacting with said wire and for substantiallyprohibiting transverse motion of said slider shoe with respect to saidwire and having a shunt for electrically connecting said currentcollecting device to said pantograph assembly, a vertically slotted armsecured to and extending vertically downward from said inverted U-shapedbracket and disposed midway between said last-mentioned hinges, saidslotted arm connected to each of said upper arms of said pantographassembly by a rigid link serially connected with a supporting arm, oneend of said supporting arm being rigidly mounted on said upper arm ofsaid pantograph assembly, thereby causing either of said upper arms tobe restrained whenever said upper arm tends to move to an unsymmetricalposition with respect to the other said upper arm.

EUGENE F. McCALEB.

No references cited.

